Data Acquisition Devices, Systems and Method for Analyzing Strain Sensors and Monitoring Component Strain

ABSTRACT

Data acquisition devices for analyzing reference objects and systems for monitoring component deformation are provided. A data acquisition device has a longitudinal axis and includes a lens assembly and an image capture device in communication with the lens assembly for receiving and processing light from the lens assembly to generate images. The data acquisition device further includes a light source and a light tube coupled at a rear end to the light source. The light tube extends along the longitudinal axis between a front end and the rear end, and is operable to transport light from the light source therethrough and emit the light from the front end. The data acquisition device further includes an actuator operable to activate the image capture device and the light source.

RELATED APPLICATIONS

This application is a continuation-in-part application of U.S.Non-Provisional patent application Ser. No. 14/687,170 having a filingdate of Apr. 15, 2015, the disclosure of which is incorporated byreference herein in its entirety.

FIELD OF THE INVENTION

The present disclosure relates generally to data acquisition devices andmethods for analyzing reference objects such as passive strainindicators, and to systems for monitoring component strain which utilizesuch devices to analyze passive strain indicators.

BACKGROUND OF THE INVENTION

Throughout various applications, consistent and accurate locating ofcomponents and surface features on the components is generally desired.Locating of the components and surface features thereon can facilitatesubsequent operations performed on or to the components and surfacefeatures.

One application wherein consistent and accurate locating is desired isin applications wherein components are subjected to numerous extremeconditions (e.g., high temperatures, high pressures, large stress loads,etc.). Over time, an apparatus's individual components may suffer creepand/or deformation that may reduce the component's usable life. Suchconcerns might apply, for instance, to some turbomachines, such as gasturbine systems.

Turbomachines are widely utilized in fields such as power generation andaircraft engines. For example, a conventional gas turbine systemincludes a compressor section, a combustor section, and at least oneturbine section. The compressor section is configured to compress air asthe air flows through the compressor section. The air is then flowedfrom the compressor section to the combustor section, where it is mixedwith fuel and combusted, generating a hot gas flow. The hot gas flow isprovided to the turbine section, which utilizes the hot gas flow byextracting energy from it to power the compressor, an electricalgenerator, and other various loads.

During operation of a turbomachine, various components (collectivelyknown as turbine components) within the turbomachine and particularlywithin the turbine section of the turbomachine, such as turbine blades,may be subject to creep due to high temperatures and stresses. Forturbine blades, creep may cause portions of or the entire blade toelongate so that the blade tips contact a stationary structure, forexample a turbine casing, and potentially cause unwanted vibrationsand/or reduced performance during operation.

Accordingly, it is desirable to monitor components for creep. Oneapproach to monitoring components for creep is to configure strainsensors on the components, and analyze the strain sensors at variousintervals to monitor for deformations associated with creep strain.However, such deformation can in many cases be on the order of 0.01% ofan original dimension, thus requiring specialized equipment for strainmonitoring. Presently known acquisition tools and techniques formonitoring such strain sensors may in some cases not provide the desiredsufficiently low-distortion, high-contrast, small scale images for theseapplications.

Accordingly, alternative systems and methods for monitoring componentstrain are desired in the art. Further, alternative data acquisitiondevices and methods for analyzing reference objects, such as passivestrain indicators, are desired in the art. Systems, devices and methodswhich provide sufficiently low-distortion, high-contrast, small scaleimages for component passive strain indicator monitoring would beparticularly advantageous.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention will be set forth in part in thefollowing description, or may be obvious from the description, or may belearned through practice of the invention.

In accordance with one embodiment of the present disclosure, a dataacquisition device for analyzing a reference object is provided. Thedata acquisition device has a longitudinal axis and includes a lensassembly and an image capture device in communication with the lensassembly for receiving and processing light from the lens assembly togenerate images. The data acquisition device further includes a lightsource and a light tube coupled at a rear end to the light source. Thelight tube extends along the longitudinal axis between a front end andthe rear end, and is operable to transport light from the light sourcetherethrough and emit the light from the front end. The data acquisitiondevice further includes an actuator operable to activate the imagecapture device and the light source.

In accordance with another embodiment of the present disclosure, asystem for monitoring component deformation is provided. The componenthas an exterior surface. The system includes a passive strain indicatorconfigurable on the exterior surface of the component, and a dataacquisition device for analyzing the passive strain indicator. The dataacquisition device includes a lens assembly and an image capture devicein communication with the lens assembly for receiving and processinglight from the lens assembly to generate images. The data acquisitiondevice further includes a light source, and a light tube coupled at arear end to the light source. The light tube extends along alongitudinal axis between a front end and the rear end, and is operableto transport light from the light source therethrough and emit the lightfrom the front end. The data acquisition device further includes anactuator operable to activate the image capture device and the lightsource, and a shell, the shell surrounding the lens assembly, the imagecapture device, the light source, and the light tube. The dataacquisition device further includes a plurality of spacers disposedproximate the front end of the light tube. Each of the plurality ofspacers extends from the shell and is sized to space the front end ofthe light tube from the exterior surface of the component when the dataacquisition device is in an operative position in contact with theexterior surface of the component.

In accordance with another embodiment of the present disclosure, amethod for analyzing a passive strain indicator is provided. The methodincludes locating a passive strain indicator portion relative to abackground portion within an image of the passive strain indicator byperforming a first analysis of the image. The method further includesidentifying passive strain indicator indicia of the passive strainindicator portion by performing a second analysis of the image. Themethod further includes conducting a quality analysis of the passivestrain indicator portion by performing a third analysis of the passivestrain indicator portion of the image, the third analysis utilizing ahigher bit-depth than the first analysis.

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdescription and appended claims. The accompanying drawings, which areincorporated in and constitute a part of this specification, illustrateembodiments of the invention and, together with the description, serveto explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appendedfigures, in which:

FIG. 1 is a perspective view of an exemplary component comprising apassive strain indicator in accordance with one embodiment of thepresent disclosure;

FIG. 2 is a top view of an exemplary passive strain indicator inaccordance with one embodiment of the present disclosure;

FIG. 3 is a side view of a system for monitoring component strain inaccordance with one embodiment of the present disclosure;

FIG. 4 is a perspective view of a data acquisition device in accordancewith one embodiment of the present disclosure;

FIG. 5 is a perspective cross-sectional view of a data acquisitiondevice in accordance with one embodiment of the present disclosure;

FIG. 6 is a side view of a data acquisition device, with variouscomponents shown in shadow for illustrative purposes, in accordance withone embodiment of the present disclosure;

FIG. 7 is a perspective view of a light tube of a data acquisitiondevice in accordance with one embodiment of the present disclosure;

FIG. 8 illustrates an image of a passive strain indicator in accordancewith one embodiment of the present disclosure;

FIG. 9 is a flow chart illustrating a method in accordance with oneembodiment of the present disclosure; and

FIG. 10 is a perspective view of an exemplary component comprising apassive strain indicator in accordance with one embodiment of thepresent disclosure.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made in detail to embodiments of the invention,one or more examples of which are illustrated in the drawings. Eachexample is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to thoseskilled in the art that various modifications and variations can be madein the present invention without departing from the scope or spirit ofthe invention. For instance, features illustrated or described as partof one embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present inventioncovers such modifications and variations as come within the scope of theappended claims and their equivalents.

Referring now to FIGS. 1 and 10, a components 10 are illustrated with apassive strain indicator 40 configured on a portion of the component'sexterior surface 11. The component 10 can comprise a variety of specificcomponents such as those utilized in high temperature applications(e.g., components comprising nickel or cobalt based superalloys). Insome embodiments, the component 10 may comprise an industrial gasturbine or steam turbine component such as a combustion component or hotgas path component. In some embodiments, such as the embodimentillustrated in FIG. 1, the component 10 may comprise a turbine blade,compressor blade, vane, nozzle, shroud, rotor, transition piece orcasing. In other embodiments, the component 10 may comprise any othercomponent of a turbine such as any other component for a gas turbine,steam turbine or the like. In some embodiments, such as the embodimentillustrated in FIG. 10, the component may comprise a non-turbinecomponent including, but not limited to, automotive components (e.g.,cars, trucks, etc.), aerospace components (e.g., airplanes, helicopters,space shuttles, aluminum parts, etc.), locomotive or rail components(e.g., trains, train tracks, etc.), structural, infrastructure or civilengineering components (e.g., bridges, buildings, constructionequipment, etc.), and/or power plant or chemical processing components(e.g., pipes used in high temperature applications).

The component 10 has an exterior surface 11 on which passive strainindicators 40 are configured. Passive strain indicators 40 in accordancewith the present disclosure may be configured on the exterior surface 11using any suitable techniques, including deposition techniques; othersuitable additive manufacturing techniques; subtractive techniques suchas laser ablation, engraving, machining, etc.; appearance-changetechniques such as annealing, direct surface discoloration, ortechniques to cause local changes in reflectivity; mounting ofpreviously formed passive strain indicators 40 using suitable mountingapparatus or techniques such as adhering, welding, brazing, etc.; oridentifying pre-existing characteristics of the exterior surface 11 thatcan function as the components of a passive strain indicator 40.

Referring now to FIGS. 1, 2 and 10, a passive strain indicator 40 isconfigured on a portion of the exterior surface 11 of the component 10.The passive strain indicator 40 generally comprises at least tworeference points 41 and 42 that can be used to measure a distance Dbetween said at least two reference points 41 and 42 at a plurality oftime intervals. As should be appreciated to those skilled in the art,these measurements can help determine the amount of strain, strain rate,creep, fatigue, stress, etc. at that region of the component 10. The atleast two reference points 41 and 42 can be disposed at a variety ofdistances and in a variety of locations depending on the specificcomponent 10 so long as the distance D there between can be measured.Moreover, the at least two reference points 41 and 42 may comprise dots,lines, circles, boxes or any other geometrical or non-geometrical shapeso long as they are consistently identifiable and may be used to measurethe distance D there between.

The passive strain indicator 40 may comprise a variety of differentconfigurations and cross-sections such as by incorporating a variety ofdifferently shaped, sized, and positioned reference points 41 and 42.For example, as illustrated in FIG. 2, the passive strain indicator 40may comprise a variety of different reference points comprising variousshapes and sizes. Such embodiments may provide for a greater variety ofdistance measurements D such as between the outer most reference points(as illustrated), between two internal or external reference points, orany combination there between. The greater variety may further provide amore robust strain analysis on a particular portion of the component 10by providing strain measurements across a greater variety of locations.

Furthermore, the dimensions of the passive strain indicator 40 maydepend on, for example, the component 10, the location of the passivestrain indicator 40, the targeted precision of the measurement,application technique, and optical measurement technique. For example,in some embodiments, the passive strain indicator 40 may comprise alength and width ranging from less than 1 millimeter to greater than 300millimeters. Moreover, the passive strain indicator 40 may comprise anythickness that is suitable for application and subsequent opticalidentification without significantly impacting the performance of theunderlying component 10. Notably, this thickness may be a positivethickness away from the surface 11 (such as when additive techniques areutilized) or a negative thickness into the surface 11 (such as whensubtractive techniques are utilized). For example, in some embodiments,the passive strain indicator 40 may comprise a thickness of less thanfrom about 0.01 millimeters to greater than 1 millimeter. In someembodiments, the passive strain indicator 40 may have a substantiallyuniform thickness. Such embodiments may help facilitate more accuratemeasurements for subsequent strain calculations between the first andsecond reference points 41 and 42.

In some embodiments, the passive strain indicator 40 may comprise apositively applied square or rectangle wherein the first and secondreference points 41 and 42 comprise two opposing sides of said square orrectangle. In other embodiments, the passive strain indicator 40 maycomprise at least two applied reference points 41 and 42 separated by anegative space 45 (i.e., an area in which the passive strain indicatormaterial is not applied). The negative space 45 may comprise, forexample, an exposed portion of the exterior surface 11 of the component10. Alternatively or additionally, the negative space 45 may comprise asubsequently applied visually contrasting material that is distinct fromthe material of the at least two reference points 41 and 42 (or viceversa).

As illustrated in FIG. 2, in some embodiments, the passive strainindicator 40 may include a unique identifier 47 (hereinafter “UID”). TheUID 47 may comprise any type of barcode, label, tag, serial number,pattern or other identifying system that facilitates the identificationof that particular passive strain indicator 40. In some embodiments, theUID 47 may additionally or alternatively comprise information about thecomponent 10 or the overall assembly, such as a turbine or otherassembly, that the passive strain indicator 40 is deposited on. The UID47 may thereby assist in the identification and tracking of particularpassive strain indicators 40, components 10 or even overall assembliesto help correlate measurements for past, present and future operationaltracking.

The passive strain indicator 40 may thereby be configured in one or moreof a variety of locations of various components 10. For example, asdiscussed above, the passive strain indicator 40 may be configured on abucket, blade, vane, nozzle, shroud, rotor, transition piece or casing.In such embodiments, the passive strain indicator 40 may be configuredin one or more locations known to experience various forces during unitoperation such as on or proximate airfoils, platforms, tips or any othersuitable location. Moreover, the passive strain indicator 40 may bedeposited in one or more locations known to experience elevatedtemperatures. For example the passive strain indicator 40 may beconfigured on a hot gas path or combustion component 10.

In some embodiments, multiple passive strain indicators 40 may beconfigured on a single component 10 or on multiple components 10. Forexample, a plurality of passive strain indicators 40 may be configuredon a single component 10 at various locations such that the strain maybe determined at a greater number of locations about the individualcomponent 10. Alternatively or additionally, a plurality of likecomponents 10 may each have a passive strain indicator 40 configured ina standard location so that the amount of strain experienced by eachspecific component 10 may be compared to other like components 10. Ineven some embodiments, multiple different components 10 of the same unitmay each have a passive strain indicator 40 configured thereon so thatthe amount of strain experienced at different locations within theoverall turbine may be determined.

Referring now to FIG. 3, a system 100 for monitoring component 10deformation is provided. System 100 may include, for example, one ormore passive strain indicators 40 which are configurable on the exteriorsurface 11 of one or more components 10 as discussed above. Further,system 100 may further include a data acquisition device 102 foranalyzing one or more reference objects, such as passive strainindicators 40.

Data acquisition devices 102 in accordance with the present disclosuremay advantageously facilitate improved passive strain indicator 40analysis. In particular, such data acquisition devices 102 mayadvantageously provide low-distortion, high-contrast, small scale imageswhich are particularly useful for component 10 passive strain indicator40 monitoring. For example, in some embodiments, data acquisitiondevices 102 in accordance with the present disclosure can provide imageshaving up to approximately 15 micron resolution, up to 0.001 millimeteroverall accuracy, and/or measurement accuracy up to 5 microstrain or0.000005 inch/inch. To provide such images, and as discussed herein,data acquisition devices 102 in accordance with the present disclosureadvantageously include a number of image optimization features, such asfor example features for providing optimal light source standoffdistances and light angles as well as features for providing optimal,consistent imaging angles relative to the reference object(s) beingimaged, such as passive strain indicators 40.

Referring now to FIGS. 3 through 7, embodiments of data acquisitiondevices 102 in accordance with the present disclosure are provided. Adevice 102 in accordance with the present disclosure defines and extendsalong a longitudinal axis 104 between a front end 106 and a rear end108. The front end 106 may generally be the end that contacts a surface,such as an external surface 11 of a component 10, for imaging purposes.As discussed herein, device 102 may be positioned such that the frontend 106 is in contact with a surface such as an external surface 11, andfurther positioned such that a reference object such as a passive strainindicator 40 is within a viewing window 109 of the device 102. Theviewing window 109 can generally be defined as the area visible to alens assembly 110 of the device 102. Light may then be received andprocessed by an image capture device 120 to generate images, and theseimages may be analyzed as discussed herein.

Device 102 may thus include, for example, a lens assembly 110 and animage capture device 120. Lens assembly 110 may generally extend betweena front end 112 and a rear end 114 along the longitudinal axis 104, andmay magnify images viewed by the lens assembly 110 for processing by theimage capture device 120. Lens assembly 110 in some embodiments may, forexample, be a suitable camera lens, telescope lens, etc., and mayinclude one or more lens spaced apart to provide the requiredmagnification. Notably, the required magnification for applications asdiscussed herein is not necessarily significantly large, and may forexample, be approximately 0.5 to approximately 2 times magnification ormore.

Image capture device 120 may generally be in communication with the lensassembly 110 for receiving and processing light from the lens assembly110 to generate images. In exemplary embodiments, for example, imagecapture device 120 may be a camera sensor which receives and processeslight from a camera lens to generate images, such as digital images, asis generally understood. Notably, the required resolution forapplications as discussed herein is not necessarily significantly large,and may for example, be approximately 1.5 Megapixels or more.

Image capture device 120 may further be in communication with suitablehardware and/or software, via for example a suitable wired or wirelessconnection, for storing and analyzing the images from the image capturedevice 120 and device 102 generally. Such hardware and/or software may,for example, generally analyze passive strain indicators 40 to determinewhether deformation and strain have occurred as discussed above.

Device 102 can further, for example, include a light source 130. Lightsource may generally provide light to illuminate a reference object,such as a passive strain indicator 40, for imaging purposes. Lightsource 130 is, in exemplary embodiments as shown, spaced from the frontend 106 of the device 102. For example, light source 130 may bepositioned proximate the front end 112 of the lens assembly 110, whichmay be spaced from the front end 106 of the device 102. Light source 130may include, for example, one or more light emitting diodes (“LEDs”) orother light emitting components 132. The light emitting components 132may, for example, be spaced apart in an annular array. Light source 130may further include a ring 134 on which the light emitting components132 are mounted and positioned. The light source 130 and light emittingcomponents 132 thereof may generally be selectively activatable and,when activated, may provide light which provides illumination within theviewing window 109.

Device 102 can further, for example, include a light tube 140 which isoperable to transmit light from the light source 130 therethrough. Lighttube 140 extends along the longitudinal axis 104 between a front end 142and a rear end 144, and is operable to transport light therethrough andemit the light from the front end 142. For example, in exemplaryembodiments as shown, light tube 140 may be coupled at its rear end 144to the light source 130, such that the light tube 140 and light source130 are in contact. The light emitting components 132, for example, maybe positioned within recesses 145 defined in the rear end 144 of thelight tube 140. When light is emitted from the light source 130, such asfrom the light emitting components 132 thereof, this light may travelthrough the light tube 140 and be emitted from the front end 142.

Light tube 140 may, for example, be formed from a suitable plastic whichallows light travel therethrough. For example, in exemplary embodiments,light tube 140 may be formed from a translucent plastic, which may ormay not be transparent. In some embodiments, light tube 140 may beformed from a material that has a critical exposure of betweenapproximately 10 mJ/cm² and approximately 14 mJ/cm² and/or an exposurethat gives 0.010 inch thickness of between approximately 50 mJ/cm² andapproximately 60 mJ/cm².

As mentioned, light travels through the light tube 140 from the rear end144 towards the front end 142, and is emitted from the front end 142. Insome exemplary embodiments, an outer surface 146 of the light tube 140may include one or more chamfered portions 147, which can assist infocusing and aiming the light as it travels through the light tube 140for optimal output. Each chamfered portion 147 of the outer surface 146may taper towards an inner surface 148 (which defines an interior 149 ofthe light tube 140) along the longitudinal axis 104. For example, asshown, a chamfered portion 147 may be provided proximate the rear end144 to initially focus the light after it enters the light tube 140.Additionally or alternatively, a chamfered portion 147 may be providedat the front of the light tube 140. This chamfered portion 147 may beproximate or may include the front end 142. In particular when thischamfered portion 147 includes the front end 142, this chamfered portion147 may focus the light as it is emitted from the front end 142 foroptimal light distribution within the viewing window 109. For example,in exemplary embodiments as shown, light may be emitted from the frontend 142 at an angle of incidence 150 of between approximately 20 degreesand approximately 50 degrees, such as between approximately 30 degreesand approximately 45 degrees. An angle of incidence within this rangemay provide optimal light distribution within the viewing window 109,particularly when viewing reference features on components, and inexemplary embodiments may be due to the chamfered portion 147 thatincludes the front end 142.

In exemplary embodiments as illustrated, light tube 140 is generallycylindrical, thus having a circular cross-sectional shape.Alternatively, however, light tube 140 may have an oval, rectangular,triangular, or any other suitable polygonal cross-sectional shape.

Notably, light tube 140 also defines the viewing window 109.Specifically, the inner surface 148 and interior 149 define the viewingwindow 109. Images of a reference object, when the device 102 is inposition on the surface on which the reference object is configured, arevisible to the lens assembly 110 and received by the image capturedevice 120 through the interior 149, as illustrated. Accordingly, frontend 112 of lens assembly 110 may be positioned proximate rear end 144 oflight tube 140.

To prevent loss of light due to emission from the light tube 140 beforethe light reaches the front end 142, an outer shroud 160 and/or andinner shroud 162 may in exemplary embodiments be included in the dataacquisition device 102. The shrouds 160, 162 may be positioned proximateand optionally in contact with the outer and inner surface 146, 148 ofthe light tube 140, respectively, and be formed form opaque materialswhich prevent light from travelling therethrough. Accordingly, lightthat encounters the shrouds 160, 162 as it is travelling through thelight tube 140 may be redirected within the light tube 140, rather thanbeing allowed to escape. For example, in exemplary embodiments one orboth shrouds 160, 162 may be formed from a suitable metal, such asaluminum. Outer shroud 160 may surround at least a portion of the outersurface 146 of the light tube 140, and inner shroud 162 may surround atleast a portion of the inner surface 148 of the light tube 140.

To further facilitate optimal lighting of the positioning of the viewingwindow 109, device 102 may further include one or more spacers 170 whichare disposed proximate the front end 142 of the light tube 140. Inexemplary embodiments, three spacers 170 are utilized, such that thedevice 102 can be optimally balanced on surfaces, such as exteriorsurfaces 11, that are both planer and surfaces that are non-planer.However, it should be understood that any suitable number of spacers iswithin the scope and spirit of the present disclosure.

The spacers 170 are sized and positioned to provide optimal spacingbetween the light tube 140 and the exterior surface 11 when the device102 is in an operative position in contact with a surface on which areference object is configured, such that optimal lighting of thereference objected is provided and optimal images are received by theimage capture device 120 from the lens assembly 110. For example, inexemplary embodiments, each spacer may be sized such that a distance 174along the longitudinal axis 104 between a front end 172 of each of theplurality of spacers 170 and the front end 142 of the light tube 140 isbetween approximately 0.25 inches and approximately 0.75 inches, such asbetween approximately 0.4 inches and approximately 0.5 inches. Thus,each spacer 170 may be sized to space the front end 142 of the lighttube 140 from the exterior surface 11 of the component 10 or otherobject by a distance 176 along the longitudinal axis 104 of betweenapproximately 0.25 inches and approximately 0.75 inches, such as betweenapproximately 0.4 inches and approximately 0.5 inches, when the device102 is in an operative position in contact with the exterior surface 11of the component 10 or other object.

Device 102 may, in exemplary embodiments, further include an actuator180. Actuator 180 may, for example, be a button, switch, or othersuitable component which can be operated to activate other components ofthe device 102. For example, actuator 180 may be in communication (via asuitable wired or wireless connection) with the image capture device 120and the light source 130. When the actuator 180 is actuated to activatethe image capture device 120 and the light source 130, the lightemitting components 132 may be activated to emit light and the imagecapture device 120 may be activated to receive one or more images. Thesecomponents may then be deactivated, either automatically or manually dueto additional actuation of the actuator 180.

Device 102 may additionally include a shell 190 which generallysurrounds and contains various other components of the device 102. Forexample, shell 190 may surround the lens assembly 110, the image capturedevice 120, the light source 130, and the light tube 140. Shell 190 mayfurther surround the actuator 180, which may be actuatable through theshell 190, or the actuator 180 may protrude through the shell 190.Notably, the front ends 172 of the spacers 170 may extend outwardly fromthe shell 190 along the longitudinal axis 104, to space the shell 190from a surface when the device 102 is in an operative position asdiscussed.

It should be noted that, in exemplary embodiments, devices 102 asdiscussed herein are hand-held devices which may be manually operatedfor image analysis as discussed herein. However, it should be understoodthat the present disclosure is not limited to hand-held devices. Rather,any suitable devices, including for example automated devices and/ordevices attached to, for example, robotic machines, etc., and which aremanually operated or automated, are within the scope and spirit of thepresent disclosure.

Referring now to FIGS. 8 and 9, the present disclosure is furtherdirected to methods 300 for analyzing reference objects, such as passivestrain indicators 40. In exemplary embodiments, an image capture device120 may be utilized to obtain images that are analyzed via a method 300in accordance with the present disclosure. However, it should beunderstood that the present disclosure is not limited image capturedevices 120 and images captured therefrom, and rather that any suitableimages of references objects may be analyzed in accordance with thepresent disclosure.

As mentioned, an image capture device 120 may be in communication withsuitable hardware and/or software, via for example a suitable wired orwireless connection, for storing and analyzing the images from the imagecapture device 120 and device 102 generally. Accordingly, an imagecapture device 120 may further include a processor 200 which may includesuch suitable hardware and/or software. In exemplary embodiments,processor 200 may perform various of the steps of method 300 asdiscussed herein.

In general, as used herein, the term “processor” refers not only tointegrated circuits referred to in the art as being included in acomputer, but also refers to a controller, a microcontroller, amicrocomputer, a programmable logic controller (PLC), an applicationspecific integrated circuit, and other programmable circuits. Processor200 may also include various input/output channels for receiving inputsfrom and sending control signals to various other components with whichthe processor 200 is in communication, such as the lens assembly 110,light source 130, image capture device 200, etc.

Method 300 may include, for example, the step 310 of locating areference object portion 314 (such as a passive strain indicator portion314) relative to a background portion 316 within an image 312 of thereference object (such as the passive strain indicator 40) by performinga first analysis of the image 312. The first analysis is generally ananalysis which differentiates the reference object portion 314 from thebackground portion 316 on the basis of differences in color depth. Firstanalysis may be performed on each individual pixel 318 or groups ofpixels 319 defining the image 312. For example, in exemplaryembodiments, a binary color depth analysis is performed on multi-pixelgroups 319. For a binary analysis to occur, the number of bits-per-pixelof the image i.e. 128, 256, etc., is divided into two groups (generallya group which includes the lighter color depths and a group whichincludes the darker color depths). Each group is categorized as areference object portion 314 or a background portion 316. For example,the binary color depth analysis may categorize pixels or multi-pixelgroups 319 that are darker color depths as denoting a reference objectportion 314, and may categorize pixels or multi-pixel groups 319 thatare lighter color depths as denoting a background portion 316.

In alternative embodiments, first analysis need not be a binaryanalysis. For example, first analysis may be a suitable greyscaleanalysis, as discussed herein, or other suitable comparison of colordepths of the pixels 318 defining the image 312.

Step 310 may generally locate the reference object portion 314 withinthe image 312. Further, in some embodiments, the information obtainedfrom the first analysis may then be compared to predeterminedthreshold(s) for such information to determine if the threshold issatisfied. A predetermined threshold may, for example, include one ormore dimensions of the reference object, desired locations andorientation of the reference object portion 314 in the plane of theimage 312, etc. In some embodiments, if the predetermined threshold issatisfied, feedback signals may be provided to the device 102 toindicate such satisfaction. For example, indicator lights 195 may beactivated.

Method 300 may further include, for example, the step 320 of identifyingreference object indicia (such as passive strain indicator indicia) ofthe reference object portion 314 by performing a second analysis of theimage 312 (such as the entire image 312 or the reference object portion314 thereof). For passive strain indicators 40, passive strain indicatorindicia may include, for example, reference points 41, 42, uniqueidentifiers 47, and other identifiable components of the passive strainindicators 40. In general, reference object indicia are identifiablecomponents of the reference object which provide some information aboutthe reference object.

The second analysis is generally an analysis which furtherdifferentiates the reference object portion 314 from the backgroundportion 316, and which differentiates the various reference objectindicia, on the basis of differences in color depth. Second analysis maybe performed on each individual pixel 318 or groups of pixels 319defining the image 312. For example, in exemplary embodiments, a binarycolor depth analysis is performed on single pixels 318. In alternativeembodiments, second analysis need not be a binary analysis. For example,second analysis may be a suitable greyscale analysis, as discussedherein, or other suitable comparison of color depths of the pixels 318defining the image 312.

Step 320 may generally further locate the reference object portion 314within the image 312, and may further facilitate collection ofinformation from the reference object of which the image 312 was taken.For example, the existence of reference points 41, 42 may be confirmed,and identifying information for the reference object may be collectedfrom the unique identifiers 47. Further, in some embodiments, theinformation obtained from the second analysis may then be compared topredetermined threshold(s) for such information to determine if thethreshold is satisfied. A predetermined threshold may, for example,include predetermined levels of indicia, such as reference points 41,42, which can be confirmed.

Method 300 may further include, for example, the step 330 of conductinga quality analysis of the reference object portion 314 by performing athird analysis of the image 312 (such as the entire image 312 or thereference object portion 314 thereof). The third analysis is generallyan analysis which further differentiates the reference object portion314 from the background portion 316, and which further differentiatesthe various reference object indicia, on the basis of differences incolor depth. In exemplary embodiments, third analysis utilizes a higherbit-depth than the first analysis. Further, in some embodiments, thirdanalysis may utilize a higher bit-depth than the second analysis. Thirdanalysis may be performed on each individual pixel 318, or onsub-sections of individual pixels. For example, pixels 318 may bedivided into 100 sub-sections, 1000 sub-sections, 10,000 sub-sections,or any other suitable number of subsections, and the third analysis maybe performed on each individual sub-section. In exemplary embodiments, agreyscale analysis is performed on the bits-per-pixel of the image i.e.128, 256, etc. For example, in some embodiments, a 256 bit-per-pixelgreyscale analysis is performed. Accordingly, each pixel 318 orsub-section thereof is categorized as having a particular color depthper the 128, 256, etc. color depth scale.

Step 330 may generally allow for the strength of the image 312 to beanalyzed by, for example, analyzing the contrast between neighboringpixels 318 or sub-sections thereof. For example, it is generallydesirable for the contrast between pixels at the border of features ofthe reference object portion 314, such as the edges of the referenceobject portion 314 or indicia thereof, to be high, thus indicating thedistinction between the reference object portion 314 or indicia thereofand the background portion 316, etc. Further, step 330 may generallyallow for the sharpness of the image 312 to be analyzed by, for example,analyzing the width in pixels 318 or sub-sections thereof of variousfeatures of the reference object portion 314. For example, it isgenerally desirable for the width of features of the reference objectportion 314, such as the edges of the reference object portion 314 orindicia thereof, to be low, thus indicating the sharpness of the imageof the reference object portion 314 or indicia thereof relative to thebackground portion 316, etc. Further, in some embodiment, theinformation obtained from the third analysis may then be compared topredetermined threshold(s) for such information to determine if thethreshold is satisfied. A predetermined threshold may, for example,include predetermined strength and sharpness levels.

Steps 310, 320 and/or 330 may generally be utilized to determine whetheran image 312 is of sufficient quality to be saved for subsequentanalysis, such as subsequent strain analysis as discussed herein. Forexample, as discussed, in some embodiments, the information obtainedfrom the color analyses in each step 310, 320, 330 may compared tovarious predetermined thresholds. In exemplary embodiments, method 300may further include the step 340 of saving the image 312 when thelocating step 310, the identifying step 320 and/or the conducting step330 each satisfy the required predetermined threshold(s). Such image 312may then be utilized in subsequent analysis of the reference object.

In some embodiments, method 300 may further include the step 350 ofcomparing the saved image 312 to one or more previously-saved images312. The previously-saved images 312 are generally images 312 that havebeen saved within the same iteration of reference object analysis, i.e.during the same operation of the device 102 and processor 200 to obtainimages during a particular time period. In general, differences betweenthe reference object portions 314, such as differences between theindicia thereof, may be analyzed. Optimally, little or no differencesshould be present, because the images are taken during a singleiteration. In general, a threshold may be set for particulardifferences, such as a threshold strain. For example, a threshold strainmay be 5 microstrain, 10 microstrain, 20 microstrain, etc. If adifference exceeds the threshold, this may indicate that outside forcesare influencing the accuracy of the images, thus allowing a user tocease analysis and perform a quality check of the associated system 100,device 102, processor 200, etc.

It should be noted that steps 310, 320 and/or 330 as discussed hereinmay in exemplary embodiments, be performed in real time as images arereceived by the processor 200 from image captures device 120.

Method 300 may further include various steps for initially operating adevice, such as device 102, to analyze a reference object. For example,method 300 may include the step 360 of activating a light source, suchas light source 130. Light source 130 may be activated (such as byprocessor 200) either automatically within an automated system ormanually in response to an input by a user, such by a user pressingactuator 180. Further, method 300 may include the step 370 of activatingthe processor 200 to analyze images. In accordance with this step, theprocessor 200 may enter a mode wherein steps 310, 320 and/or 330 areperformed. Such activation may occur (such as by processor 200) eitherautomatically within an automated system or manually in response to aninput by a user, such by a user pressing actuator 180. Further, method300 may include the step 380 of contacting the exterior surface on whichthe reference object is configured, such as the exterior surface 11 ofthe component 10, with a device such as device 102. In exemplaryembodiments as discussed herein, spacers 170 may contact the exteriorsurface 11. Such contact may occur either automatically within anautomated system (such as by processor 200) or manually by a user.Notably, in exemplary embodiments, step 370 may occur after step 360.Steps 310-350 may occur after such steps.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

What is claimed is:
 1. A system for monitoring component deformation,the component having an exterior surface, the system comprising: apassive strain indicator configurable on the exterior surface of thecomponent; and a data acquisition device for analyzing the passivestrain indicator, the data acquisition device comprising: a lensassembly; an image capture device in communication with the lensassembly for receiving and processing light from the lens assembly togenerate images; a light source; a light tube coupled at a rear end tothe light source and extending along a longitudinal axis between a frontend and the rear end, the light tube operable to transport light fromthe light source therethrough and emit the light from the front end; anactuator operable to activate the image capture device and the lightsource; a shell, the shell surrounding the lens assembly, the imagecapture device, the light source, and the light tube; and a plurality ofspacers disposed proximate the front end of the light tube, each of theplurality of spacers extending from the shell and sized to space thefront end of the light tube from the exterior surface of the componentwhen the data acquisition device is in an operative position in contactwith the exterior surface of the component.
 2. The system of claim 1,wherein the data acquisition device further comprises an outer shroudsurrounding at least a portion of an outer surface of the light tube. 3.The system of claim 1, wherein an outer surface of the light tubecomprises a chamfered portion, the chamfered portion tapering towards aninner surface of the light tube along the longitudinal axis.
 4. Thesystem of claim 3, wherein the chamfered portion includes the front end.5. The system of claim 1, wherein light is emitted from the front end ofthe light tube at an angle of incidence of between approximately 20degrees and approximately 50 degrees.
 6. The system of claim 1, whereineach of the plurality of spacers is sized to space the front end of thelight tube from the exterior surface of the component by a distancealong the longitudinal axis of between approximately 0.25 inches andapproximately 0.75 inches when the data acquisition device is in anoperative position in contact with the exterior surface of thecomponent.
 7. The system of claim 1, wherein the data acquisition devicefurther comprises a processor, the processor configured for: locating apassive strain indicator portion relative to a background portion withinan image of the passive strain indicator by performing a first analysisof the image; identifying passive strain indicator indicia of thepassive strain indicator portion by performing a second analysis of theimage; and conducting a quality analysis of the passive strain indicatorportion by performing a third analysis of the passive strain indicatorportion of the image, the third analysis utilizing a higher bit-depththan the first analysis.
 8. The system of claim 1, wherein the componentis a turbine component.
 9. A data acquisition device for analyzing areference object, the data acquisition device having a longitudinal axisand comprising: a lens assembly; an image capture device incommunication with the lens assembly for receiving and processing lightfrom the lens assembly to generate images; a light source; a light tubecoupled at a rear end to the light source and extending along thelongitudinal axis between a front end and the rear end, the light tubeoperable to transport light from the light source therethrough and emitthe light from the front end; and an actuator operable to activate theimage capture device and the light source.
 10. The data acquisitiondevice of claim 9, further comprising an outer shroud surrounding atleast a portion of an outer surface of the light tube.
 11. The dataacquisition device of claim 9, further comprising an inner shroudsurrounding at least a portion of an inner surface of the light tube.12. The data acquisition device of claim 9, wherein an outer surface ofthe light tube comprises a chamfered portion, the chamfered portiontapering towards an inner surface of the light tube along thelongitudinal axis.
 13. The data acquisition device of claim 12, whereinthe chamfered portion includes the front end.
 14. The data acquisitiondevice of claim 9, wherein light is emitted from the front end of thelight tube at an angle of incidence of between approximately 20 degreesand approximately 50 degrees.
 15. The data acquisition device of claim9, further comprising a plurality of spacers disposed proximate thefront end of the light tube.
 16. The data acquisition device of claim 9,further comprising a processor configured for: locating a referenceobject portion relative to a background portion within an image of thereference object by performing a first analysis of the image;identifying reference object indicia of the reference object portion byperforming a second analysis of the image; and conducting a qualityanalysis of the reference object portion by performing a third analysisof the reference object portion of the image, the third analysisutilizing a higher bit-depth than the first analysis.
 17. A method foranalyzing a passive strain indicator, the method comprising: locating apassive strain indicator portion relative to a background portion withinan image of the passive strain indicator by performing a first analysisof the image; identifying passive strain indicator indicia of thepassive strain indicator portion by performing a second analysis of theimage; and conducting a quality analysis of the passive strain indicatorportion by performing a third analysis of the passive strain indicatorportion of the image, the third analysis utilizing a higher bit-depththan the first analysis.
 18. The method of claim 17, wherein the firstanalysis is a binary analysis of multi-pixel groups of the passivestrain indicator portion of the image.
 19. The method of claim 17,wherein the second analysis is a binary analysis of single pixels of thepassive strain indicator portion of the image.
 20. The method of claim17, wherein the third analysis is a 256 bit-per-pixel greyscaleanalysis.
 21. The method of claim 17, further comprising the step ofactivating a light source.
 22. The method of claim 17, furthercomprising the step of saving the image when the locating step, theidentifying step, and the conducting step each satisfy a predeterminedthreshold.
 23. The method of claim 22, further comprising comparing theimage to a previously-saved image.